Re: [PATCH 4/7] mm/thp: fix page_address_in_vma() on file THP tails

[Matthew Wilcox]

On Tue, Jun 01, 2021 at 02:11:22PM -0700, Hugh Dickins wrote:
> From: Jue Wang <juew@xxxxxxxxxx>
> 
> Anon THP tails were already supported, but memory-failure may need to use
> page_address_in_vma() on file THP tails, which its page->mapping check did
> not permit: fix it.
> 
> hughd adds: no current usage is known to hit the issue, but this does fix
> a subtle trap in a general helper: best fixed in stable sooner than later.
> 
> Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
> Signed-off-by: Jue Wang <juew@xxxxxxxxxx>
> Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>

Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>